I’m out of my weight class here, but formulas exist for calculating mechanical advantage of compound pulley systems like this. I’m just focusing on the task in the north country for this machine.
Grasse River (1958) is dedicated to the Saint Lawrence Seaway and based in Massena NY, along with tugs Robinson Bay (1958) and
Performance (1997). By the way, road distance from Massena NY to the sixth boro is over 350 miles!!
Perversely or providentially, Grasse River was the last ship produced by American Shipbuilding on the Buffalo River, before the shipyard closed, a victim of the opening of the Saint Lawrence Seaway.
Plans have been set in motion to replace Robinson Bay, but the 300 t. capacity Grasse River is there, on call, dedicated as a “mitre-gate lifter” in the case of damage. It’s sort of like the tow trucks on the ready at the Lincoln Tunnel to expeditiously drag out a wreck should a mishap occur inside the tunnel.
Seeing the size of the superstructure, I erroneously first assumed Grasse River was self-propelled.
All photos by Will Van Dorp, whose previous 21 “specialized” posts can be found here.
And let me add a postscript here about the location in Buffalo where Grasse River was built. The shipyard was where a vacant lot across the street from Tewksbury Restaurant finds itself today. The Tewksbury reference here is to one of two “runaway” ships that destroyed a bridge on the Buffalo in January 1959, a month when no ships were supposed to be traveling on the river. The ships involved were MacGilvray Shiras and Michael K. Tewksbury.
In that same neighborhood, Harbor Inn once served as a community institution as well.
Buffalo’s First Ward are the focus of an entire blog, as you can see here.
5 comments
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November 2, 2017 at 3:21 pm
Charles Gallo
Count the number of wires going to the moving block – that is the advantage (less friction)
1 = 1:1. 2 = 2:1 etc
November 3, 2017 at 12:47 am
sfdi1947
Really a smaller medium Barge Crane will send you a pic of the BC Pennsylvania, she carries two “Battle” Class 76′ harbor tugs on her fore deck for overseas deployments.
November 3, 2017 at 8:02 pm
Richard Tobacco
Will, count the number of lines lifting the object. Ignore lines supporting booms🙄
Sent from my iPhone
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November 3, 2017 at 8:31 pm
tugster
Charles and Richard– Thx. sfdi1947 . . . the greatest lift capacity crane i’ve ever seen is this one: https://tugster.wordpress.com/2013/07/27/jr-20/ i understand there’s one in Korea that lifts 4000 tons.
November 3, 2017 at 8:31 pm
tugster
and Richard– good to hear from you.